Well done!

I was agreeably surprised by the controls. In fact I found them pretty comfortable.

The memory footprint seems to be a little large, though. Perhaps I'm wrong, but I think that 280MB is pretty much for such a game.

And maybe you could use external textures for your cube models. Then they wouldn't waste so much disk space.

It's just a vague idea, but perhaps you could play a sound when the cubes click into place after they were rotated. An "Einrast-Geräusch", you know? ; )